The formula is based on the law of gravity, which states that objects accelerate toward the earth at a constant rate of approximately 32.2 fps/s.
To determine the speed, you will need to know the horizontal distance that the vehicle traveled through the air (Distance), the difference in height between the location that the vehicle left its supporting surface, and the location where the vehicle landed (Height). The Height will be a negative number if the vehicle landed below the height that it left its supporting surface. Finally, you'll need to know the Grade of the surface where the vehicle began to travel through the air. This is determined by dividing the rise (verticle distance) of the take-off surface by the run (horizontal distance) of the take-off surface. A level surface will have a grade of 0.
